Method of forming fluid turbine elements and the like



Oct. 19, 1954 H. 1.. MISCH 2,691,812

METHOD OF FORMING FLUID TURBINE ELEMENTS AND THE LIKE Filed April 11, 1949 5 sheets-sheet 1 INVENTOR. Herbs/ t M [sch BY ATITOENEK H. L. MISCH Oct. 19, 1954 METHOD OF FORMING FLUID TURBINE ELEMENTS AND THE LIKE 5 Sheets-Sheet .2

Filed April 11, l949 IN VEN TJOR. L- Misc/7 I Herbal "t ATTORNEK H. L. MISCH Oct. 19, 1954 METHOD OF FORMING FLUID TURBINE ELEMENTS AND THE LIKE Filed April 11, 1949 5 Sheets-Sheet 3 I'NVENTbR. Herbert L. M/lsc/I ATTOENEK Oct. 19, 1954 H. L. MISCH 2,691,812

METHOD OF FORMING FLUID TURBINE ELEMENTS AND THE LIKE Filed April 11, 1949 v 5 Sheets-Sheet 4 INVENTOR.

ATTORNEY.

Herbert L. Misc/7 Oct. 19, 1954 H: L. Misc 2,691,812

METHOD OF FORMING FLUID TURBINE ELEMENTS AND THE LIKE Filed April 11, 1949 5 Sheets-Sheet 5 /02 /06 l j I /06 IN VEN TOR.

Herbert L. Misch A TTOEA/EY Patented Oct. 19, 1954 METHOD OF FORMING FLUID TURBINE ELEMENTS AND THE LIKE Herbert L. Misch, Toledo, Ohio, assignor to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application April 11, 1949, Serial No. 86,776

9 Claims. 1

This invention relates to transmissions and more particularly to the making of fluid energizing, energy absorbing and fluid deflecting members of fluidoperated transmissions of the torque converter .and fluid coupiing types.

In the operation of devices of these types torque is imparted to a fluid by a rotatable vaned impeller, and torque is absorbed from the fluid by a rotatable vaned turbine member. In the torque converter the ,fiuid is redirected by a vaned reaction member in such a manner that a backwardly directed forceis exerted on the reaction member to increase the torque exerted on the turbine or driven member.

For most efficient operation the vanes of the impeller, turbine and reaction members interposed between outer shell and inner shroud members should embody different contours, and the fluid channels through the various members should be free from abrupt changes of contour that would cause turbulence and increase the resistance to fluid fiow therethrough. It is therefore desirable that well rounded fillets be prov-ided at the junctures of the edges of the vanes with the outer shell and the inner shroud members to minimize resistance to fluid fiow.

In my copending application Serial Number 52,078, filed September 30, 1948, I disclosed a over edges of the vanes were forced into intimate contact with the surfaces of the shell and shroud members by the application of pressure urging the shell and shroud members toward each other. The edges of the vanes were bent outwardly to provide the desired continuous contact with the shell and shroud members thereby compensating for manufacturing irregularities in the vanes. Clamping fixtures engaging the shell and shroud members were employed to hold the bent over edgesof .the vanes in the desired contacting position with the shell and shroud members, and the assembly thus formed was subjected to heat for brazing or otherwise bonding the vanes to the shell and shroud members. It was necessary that the clamping fixtures remain on the shell and shroud members during the brazing orother fusing operation. This necessitated that clamping fixtures be provided for each assembly being brazedat a given time, and resulted in-an undesirable expenditure for tooling.

An object of the present invention is therefore to provide an improved method of holding fluid deflecting vanes in a desired assembled relation in spaced shell and shroud members without the use of expensive clamping fixtures at the time of the heating operation.

A further object is in the provision of securing means as an integral part of one of the members for attachment to the other member for holding the parts in the clamped position during the brazing or other fusing operation whereby the vanes are secured to the shell and shroud members.

Still a further object of the invention resides in the use of a holding member in the form of an annular diaphragm carried by an inner shroud and adapted to be secured to an outer shell as by spot welding to maintain a plurality of spaced vanes in a predetermined clamped position relative to the shroud and shell members while the vanes are being secured to the shell and shroud members by a brazing or other fusing operation.

Another object of the invention is to provide angularly related reenforcing members carried by spacedshell and shroud members to render the shell and shroud members sufiiciently stiff that stamped contoured vanes having bent over edges can be compressed between them thus compensating for manufacturing irregularities by crushing the edges of the vanes into firm surface contact with the surfaces of the shell and shroud members.

Still another object resides in the use of a diaphragm shaped member carried by either the shroud or shell member, and adapted to be secured to the other as by a Welding operation to maintain the edges of contoured vanes in a predetermined position relative to the shell and shroud members preparatory to bonding the vanes to the shell and shroud members by a brazing or other fusing operation.

A further object of the invention is to provide a novel method of securing vanes to spaced shell and shroud members.

Yet another object of the invention resides'in the provision of a method of using a member shaped in the form of an annular yielding diaphragm formed on one member and adapted to be spot welded to the reenforcing flange formed on the other of the spaced shell and shroud members tomalntain the shell and shroud members in a predetermined clamped position relative to a plurality of spaced vanes interposed therebetween while brazing or otherwise bonding the elements together whereupon the diaphragm may then be removed.

Still a further object of the invention is to provide an improved method of maintaining pressure on fluid deflecting vanes interposed between spaced shell and shroud members by securing as by welding a yielding diaphragm shaped member formed on one of a pair of the shell and shroud members to the other of said members to hold the assembly in a substantially predetermined position without resorting to the use of clamping fixtures or other tooling while brazing or otherwise bonding the elements together whereupon the diaphragm may then be removed.

Other objects and advantages of this invention will appear from the following description and appended claims, reference being had to the accompanying drawings which form a part of this specification, and in which:

Fig. 1 is a sectional view of a fluid torque converter embodying elements made in accordance with this invention.

Fig. 2 is a fragmentary sectional view taken substantially on the line 2--2 of Fig. 1, looking in the direction of the arrows.

Fig. 3 is a sectional view of an impeller illustrating the fluid deflecting vanes positioned in the outer shell and inner shroud members with the shell and shroud members secured together as by a Welding operation.

Fig. 4 is a view similar to Fig. 3 showing the impeller in the completed form.

Figs. 5 and 6 are views similar to Figs. 3 and. 4 but illustrating the first stage turbine member of a torque converter.

Fig. '7 is a perspective view illustrating one of the fluid deflecting vanes of the first stage turbine.

Fig. 8 is a fragmentary front elevational view partly in section of the first stage turbine member illustrated in Fig. 6.

Figs. 9 and 10 are views similar to Figs. 3 illustrating a reaction member.

Figs. 11 and 12 are also views similar to Figs. 3 and 4 illustrating a second stage turbine member.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring now more particularly to Fig. 1, it will be noted that a crankshaft or driving shaft I0 is provided with a disk I2; having a starter gear I4 secured thereto. A driving member I6 is secured to the disk I2 as by screws I8, and has a hub 26 projecting into the end of the crankshaft or driving shaft III. A driven shaft 22 aligned with the driving shaft I0 is journalled on a bearing 24 in the hub 20 of the driving member I6.

An impeller shell 26 having a flange 28 is secured to the driving member I6 as by screws 30. At its opposite end the impeller shell 26 has an inwardly directed flange 32 secured to a flange 34 of a sleeve 36 as by screws 38, the sleeve 36 preferably having splines 40 to drive a pump to supply fluid under pressure to actuate various controls of the transmission.

A housing having a rear section 42 is provided to overlie the impeller shell 26 and to support the sleeve 36 through a bearing 44. An oil seal 46 interposed between the rear section of the housand 4 ing 42 and the sleeve 36 is provided to prevent the escape of oil between the sleeve 36 and the housing 42. The rear section 42 of the housing is secured to a front housing section 48 by means of screws 50, and the front housing 48 is secured to a portion of an engine such as a cylinder block 52 in any suitable manner.

In the embodiment illustrated a direct drive clutch is interposed between the driving member I6 and the driven shaft 22 to provide a direct drive in parallel with the torque converter when the clutch is engaged. The driving member I6 is provided with splines 54 adapted to receive a clutch backing plate 56 abutting axially extended portion 51 of the impeller shell 26. A clutch driving disk 58 is slidably mounted on the splines 56 to subject a clutch driven plate 60 to pressure thereby transferring a drive to the shaft 22 through a resilient coupling such as a plurality of coiled springs 62 inter-posed between the driven plate 66 and a flange 64 of a hub 66 secured to the driven shaft 22 by splines 68. The springs are positioned in circumferentially extending slots formed in the driven plate 66 and the flange 64, a disk I6 secured to the driven plate 66 being provided to balance the driving forces exerted on the springs 62.

The impeller shell 26 is provided with spaced bosses 96 adapted to receive radially extended attaching tabs 62 of an impeller I adapted to be secured thereto by screws 94. The impeller I has an outer shell 96, an inner shroud 98, and a plurality of spaced fluid energizing vanes I06 interposed between and secured to the outer shell 66 and to the inner shroud 98.

The impeller I imparts energy to a circulating fluid and discharges it to a first stage turbine TI having an outer shell I62 and an inner shroud I64 interconnected by energy absorbing vanes I66. The outer shell I62 of the turbine TI has an inwardly directed flange I68 secured by means of screws III) to the hub 66 splined to the driven shaft 22.

The inner shroud I04 of the first stage turbine TI is provided with a plurality of spaced bosses II2 to receive an attaching flange H4 carried by an inner shroud II6 of a second stage turbine T2 adapted to be secured thereto by screws H8. The second stage turbine T2 has an outer shell I26 spaced from the inner shroud H6, and a plurality of vanes I22 are interposed between and are secured to the inner shroud I I6 and the outer shell I26.

A reaction member R is interposed between the first and second stage turbines TI and T2, and has an inner shroud I24 and an outer shell I26 with vanes I23 interposed therebetween. The outer shell I26 is provided with an inwardly extending flange I36 adapted to be secured by means of screws I32 to a flange I34 of a sleeve I36 interposed between the sleeve 36 rotatable with the impeller shell 26 and the driven shaft 22. The sleeve I36 is provided with splines I38 adapted to receive a one-way clutch to restrain the reaction member R from rotating backwardly in the fluid circuit when the device is operating as a torque converter, and to permit it to rotate forwardly in the circuit when the device is operating as a fluid coupling, at which time power is transmitted from the driving member to the driven member with no multiplication of torque.

My copending application Serial Number 52,078 discloses an improved method of forming the vanes of a torque converter or a fluid clutch in such a manner that bent over edges I40 as illustrated in Fig. 2 are formed at the edges of the vanes which contact the outer shell and the imier shroud of the various members. Spaced locating means such as I42 in Fig. 2, and I44 in Fig. 1 are employed to locate the vanes in the proper spaced relation in the shell and shroud members.

In order to overcome the necessity of providing holding fixtures for each assembly being brazed or other otherwise treated at a single time to hold the bent over edges of the vanes in intimate contact with the surfaces of the shroud and shell members I have devised an improved method of securing the members together in such a mannerthat clamping fixtures are unnecessary.

Referring now to 3 illustrating the formation of the impeller I, it will b noted that the outer shell '83 and the inner shroud 98 are provided with reenforcing flanges hi l and M8 at their inner diameters to strengthen these por tions of the unit and prevent them from flexing to any material degree when subjected to the necessary relatively high pressure required to crush and hold the bent over edges ltd of the vanes in flrm contact with the shell and shroud members. The outer diameter of the shell $8 is provided with a radial flange I56 preferably erminating slightly forwardly of the outlet ends I52 of the impeller vanes Iilll. The inner shroud 98 is also provided with a radial flange ib l preferably in the form of an annular diaphragm having its rear surface positioned slightly forwardly of the outlet ends 253 of the impeller vanes and adapted to engage the forward surface of the flange I'sil when the vanes ills have been compressed between the outer shell 96 and the inner shroud 98 to position their bent over edges its in the desired firm contact with the surfaces of the shell and shroud members.

A suitable insulator i5ii capable of withstanding'relatively high temperature, such as a piece of mica, is interposed between the ends 552 of the vanes iiiil and the adjacent surface of the flange I54. The i553 and ltd are then secured together in any convenient manner as by spot welding indicated at I58 to maintain all the parts in position forming an assembly. The elements forming the assembly may then be joined together metallurgically to form the do sired element.

The operation of making this impeller is accurately locate them. The insulating material I56 is then secured to the ends 552 of the vanes, or "is secured to the surface of the diaphragm shaped member 554 of the inner shroud 98.

The shroud 93 is then positioned on the vanes Hit With its convex surface contacting the angularly related flanges of the vanes. Pressure from any suitable source, such as a press is exerted to urge the shroud 93 and the shell 96 toward each other, a suitable fixture being provided to spread the lead over a relatively large surface area of the shell and shroud members.

The shell, shroud and vanes ar proportioned The vanes are positioned on the locators I 32 and Hit to 6. so that when the surface of the diaphragm shaped member I54 carried by the shroud 98 engages the flange I50 carried by the shell 96 the bent over edges I40 of the vanes are positioned in firm contact with the concave surface of the outer shell 96 and th convex surface of the inner shroud 98. The diaphragm shaped member I54 and the flange I58 are then secured together as by the spot welding I53 or in any other suitable manner to hold the vanes in the desired intimate contact with the shell and shroud members. The pressure eierted on the shell and shroud members to force the bent over edges I40 of the vanes to the desired contacting position with the shell and shroud members may then be released, and the diaphragm shaped member 854 exerts a yielding force to maintain the bent over edges I40 of the vanes in the desired contacting position with the shell and. shroud members.

If the members are to be secured together by a brazing operation, suitable soldering material such as a copper alloy is applied to the edges of the vanes which contact the shell and shroud members either before or after the members are assembled. It will of course b apparent that the solder can be applied in any desired manner as by spraying, painting the'contacting edges of the vanes with a soldering solution, or otherwise.

After the soldering agent has been applied, the assembly is subjected to the heat of a brazing operation, preferably in th presence of an inert atmosphere to minimize oxidation. It will be noted that the insulating material Edd prevents the ends I52 of the vanes H3 3 from fusing with the flange i5 5 carried by the inner ShrOlld til. It will of course be apparent that the assembly may be joined together metallurgically in any desired manner as by welding Or fusing or in any other convenient manner.

When the assembly has thus been secured together, the reenforcing flanges Hit and U58 car" ried at the inner edges of the outer shell and the inner-shroud members 538 and 93 are removed by any suitable machining operation, and the portion of the diaphragm shaped member its which overlies the ends of the vanes I tail is also removed by any suitable machining operation. The assembly is then complete and ready for use after drilling the apertures ibi'i in the flanges and the portion of the diaphragm shaped mem ber ltd secured to the flange Illt as illustrated in Fig. 4 to receive the screws Si l illustrated in Fig. l to secure the impeller I to the impeller shell 26.

The first stage turbine TI more clearly il1ustrated in Figs. Band 6 is fabricated in a manner similar in many respects to the impeller I illustrated in Figs. 8 and 4.

The inwardly directed flange I 98 carried by the outer shell Elli for securing the turbine to the hub 68 splined to the driven shaft 22 reenforces the inner portion or the outer shell. A room forcing and locating flange IE2 is formed on the outer periphery of the outer shell Hi2, and preferably is positioned slightly beyond the inlet edges I64 of the turbine vanes Illa as illustrated in Fig. 5.

' Th inner periphery of the inner shroud Iild is provided with a reenforcing flange lit to in" crease the rigidity of this portion or" the shroud I04. lhe outer periphery of the inner shroud IIl l projects somewhat beyond the inlet edges of the turbine vanes I06, and is preferably provided with an internal annular groove I68. I

gase

A member in the form of an annular diaphragm I10 has an axially extending portion II2 adapted to project into the axially extending portion of the inner shroud I04 with or without a press fit and has a radially inwardly directed flange I14 having spaced apertures to receive the second stage turbine attaching bosses H2. The bosses II2 are formed with projections adapted to extend through the apertures and be peened over as illustrated at I16 to retain the bosses in place until the assembly is fused together as hereinafter more fully described. The diaphragm shaped member II is provided with a radially outwardly extended portion I78 adapted to align with and abut the locating flange I62 formed on the outer shell I02. The portion I18 of the member I10 is provided with an annular projection I00 adapted to exert pressure on the inlet edges I04 of the vanes I00 through an insulator I82 to insure firm contact between the bent over edges of the vanes and the contacted surfaces of the shell and shroud members I02 and I04 as the assembly is moved to the position illustrated in Fig. 5.

In the formation of the first stage turbine TI the outer shell and inner shroud members I02 and I04 are formed with the reenforcing flanges thereon in any suitable manner as by a stamping operation. A plurality of the vanes I06 are formed as disclosed in my copending application Serial Number 52,078, and are positioned on the locators provided between the outer shell and the inner shroud. The diaphragm shaped member I10 having the bosses II2 secured therein is positioned as illustrated in Fig. 5 with the annular projection I80 adapted to exert pressure on the inlet edges I64 of the turbine vanes I06 through the insulating material I82. The assembly thus formed is positioned in a press or other suitable mechanism and pressure is exerted to move the diaphragm shaped member I10 axially in the direction of the shell I02. The member I10 abuts the outer edge of the inner shroud I04 at the juncture between its axially extended portion I12 and its radially extended portion I18 thereby forcing the bent over edges of the vanes I06 into firm contact with the concave surface of the outer shell I02 and the convex surface of the inner shroud I04. The diaphragm shaped member I10 is proportioned so that when its radially extended portion I18 contacts the flange I62 of the outer shell I02, the vanes I06 will be positioned in the desired relation in the shell and shroud members. The member I78 is then secured to the flange I82 in any suitable manner as by spot welding illustrated at I84 to hold the parts in position forming an assembly. The diaphragm flexes slightly to exert a yielding force to maintain the bent over edges of the vanes in firm contact with the shell and shroud members.

With the assembly thus formed the whole is subjected to the heat of a brazing or fusing op eration, such as a copper brazing process to securely fasten the vanes I06 to the shell and shroud members I02 and I04 in the manner described in connection with the impeller I.

It will of course be understood that before being subjected to the brazing operation the edges of the vanes I06 which contact the shell and shroud members are treated in such a manner that solder or other brazing agent is applied thereto.

Copper or other suitable soldering agent may also be interposed between the axially extend ing portion I12 of the fixture 110 and the contacting inner surface of the shroud I04. One desirable method of applying solder at this location resides in positioning a copper wire in the internal groove I68 formed in the outer extremity of the inner shroud I04. The brazing operation is preferably performed in the presence of an inert gas to minimize oxidation. I

After the brazing operation has been performed a portion of the diaphragm shaped member I10 is cut away from the shell and shroud members in any suitable manner as by a machining operation severing the outer shell I02 and inner shroud I04 at a point substantially in radial alignment with the inlet edges I64 of the vanes I06. The reenforcing flange I06 formed on the inner shroud I04 is severed somewhat beyond the outlet from the vanes I06 as illustrated in Fig. 6. The bosses II2 are then threaded as illustrated at I to receive the screws I I8 which secure the second stage turbine T2 thereto.

The formation of the reaction member R. is similar in many respect to the formation of the other members described above, and as illustrated in Figs. 9 and 10. The inner shroud I24 is provided with a reenforcing flange I90, and the outer shell I26 is provided with reenforcing flanges I92 and I94 positioned at its opposite ends. The inwardly directed flange I30 by which the reaction member is secured to the sleeve I36 as illustrated in Fig. 1 is preferably secured to the outer shell between the radially extended flanges I92 and I94.

A diaphragm shaped member I96 is provided with an annular projection I68 adapted to exert pressure on the adjacent edges 200 of the vanes I28 through an insulating member 202. In the formation of the reaction member the vanes I28 are assembled in the outer shell I26 by means of locators similar to the locators I42 and I44 described above. The inner shroud I24 is positioned against the vanes, and pressure is exerted through the annular projection I98 of the fixture I96 to force the bent over edges of the vanes into the desired intimate contact with the inner shroud and outer shell members I24 and I26 respectively. When the flanges I00 and I02 carried by the shroud and shell members are contacted by the surfaces 204 and 206 of the diaphragm shaped member I96, the vanes are positioned in the desired relation to the shroud and shell members. The surfaces 204 and 206 of the diaphragm shaped member I06 are then secured to the flanges I and I92 of the shroud and shell members as by spot welding illustrated at 208 and 2I0 whereupon the assembly is ready for the brazing or other fusing operation to secure the assembly together as described in connection with the other assemblies.

After the assembly has been secured together, the flanges I90, I92, and I94 are removed as by any suitable machining operation whereupon the reaction member as illustrated in Fig. 10 is complete. The inwardly directed flange I30 is drilled as illustrated at 2I2 to receive the screws I32 by which the reaction member is secured to the sleeve I38 as illustrated in Fig. 1.

The second stage turbine T2 is formed in a manner substantially the same as that described in connection with the formation of the reaction member. It will be noted that the inner shroud H0 is provided with reenforcing flanges 220 and 222 and that the outer shell I20 is provided with reenforcing flanges 224 and 226. A diaphragm shaped member 228 has an annular projection 230 adapted to exert force on the edges 232 of the vanes I22- through the insulating material 234. When the elements have been assembled and forced into the desired relation by the application of pressure through the diaphragm shaped member 2-28 as described in connection with. the for mation of the other elements the surfaces 236 and.238 of the member 228 contactthe flanges 2'22 and 22B of the inner shroud and outer shell members.- These flanges are then secured to gether as by spot welding illustrated at 24! and 242 The assembly is then subjected to the brazin or other fusing operation and the I'eenforciIlg flanges 220, 225 and 226 are removed. The flange 222 is drilled as illustrated at 244 in Fig. 12- to receive the screws H3 which as illustrated in- Fig. ,1 secure the second stage turbine to the bosses H2 of the first :gtage turbine Ti.

It will of course be understood that the vanes of the various members may embody any desired contour as more clearly pointed out in copending application Serial Number 52,078. The showing of the vanes in Figs. '7 and 8 is merely for illustrative purposes and discloses vanes of a type which have provento be desirable for use in the first stage turbine Tl.

It will be understood that various forms of the invention other than those described above may beused without departing from the spirit or scopeof the invention.

I claim:

l. The method of makin a rotatable part of a fluid transmission which comprises forming shell and shroud members with radially extending flanges, oneof'said flanges taking the form of of a yielding diaphragm, positioning a plurality of fluid deflectin vanes between said members, pressing the shell and shroud members to a position which said flanges are in contact with eachother and the vanes are in flrm edge contact with the shell and shroud respectively, securing flanges together'to hold all partsin position forming an assembly, releasing the pressing action sothatthe diaphragm may exert a yielding force to hold the shell and shroud in contact withthe edges of the vanes, heating the assem- 'bi'y to metallurgical-1y join' all contacting parts,

and thereafter removing such portions of the, flanges as are unnecessary to the operation of the rotatable member,

2. The method of making a rotatable part of a fluid transmission which comprises forming shell and shroud members, having reenforcing flanges, one of said flanges taking the form of a yieldingdiaphragm, positioning a plurality of vanes between said members, assembling the shell and shroud members with said diaphragm overlapping a flange of the other member, positioning insulating material between said diaphragm and the vanes, pressing the shell and shroud members toward each other to engage the diaphragm with the flange of. the other member and with the vanesin firm edge contact with the shell and shroud members, securing said flanges together to hold all parts in position forming an assembly, releasing said pressing action so that said diapl" 'agm exert a yielding force to hold the shell and shroud in contact with the edges of as vanes, heating the assembly to join all uninszilat parts, and thereafter removing the i .lation and such portions of the flanges and the diaphragm as are unnecessary to the operation of said rotatable part.

3. The method of making a rotatable member of a fluid transmission which comprises forming outer shell and inner shroud members having reenforcing flanges, at least one of said flanges being yieldable, positioning a plurality of fluid deflecting vanes between said shell and shroud members, pressing the shell and shroud members toward each other to bring two of said reenforcing flanges into overlapping contact and to position the edges of the vanes in firm contact with the surfaces of the shell and shroud members, securing the overlapping flanges of said shell and shroud members together by attaching a portion of one of the reenforcing flanges carried by one of the members to the other member, releasing said pressin action, then metallurgically joining the vanes to the shell and shroud members, and thereafter removing certain of the reenforcing flanges from the shell and shroud members.

4. The method of forming a rotatable member of a fluid transmission which comprises forming double walled fluid deflecting vanes having diverging bent over edges, forming outer shell and inner shroud members having reenforcing flanges, one of said flanges taking the form of a yielding diaphragm, interposing a plurality of said vanes between formed shell and shroud members, urging the shell and shroud members toward each other to bring said diaphragm into overlappin position with a flange on the other of said members and to dispose the bent over edges of the vanes in firm contact with the confronting surfaces of the shell and shroud members, pressing, said members together while securing the flange and diaphragm of said shell and shroud members to each other by spot welding overlappin portions thereof, releasing said pressing action so that the diaphragm may exert a yielding force to hold said members together in contact with the edges of the vanes, metallurgically joining the vanes to the shell and shroud members, and thereafter removing certain of the reenforcing flanges from the shell and shroud. members.

5. The method of making a rotatable member of a fluid transmission which comprises forming a plurality of fluid deflecting vanes each having diverging bent over edges, forming outer shell and inner shroud members each having a reenforcing flange at its outer and inner periphery, at least one of said flanges being yieldable, positioning a plurality of said fluid deflecting vanes between said shell and shroud members, pressing one of the reenforcing flanges of the shroud into firm contact with one of the reenforcing flanges of the shell to position the bent over edges of each of the vanes in substantial surface contact with the confronting surfaces of the shell and shroud members, securing the shell and shroud members in said position relative to each other by securing said reenforcing flange carried by one of the members to the contacting reenforcing flange carried by the other member, releasing said pressing action, metallurgically joining the vanes to the shell and shroud members, and thereafter removingcertain of the reenforcing flanges from the shell and shroud members.

6. The method of making a fluid transmission rotor which comprises forming outer shell and inner shroud members having reenforcing flanges at their inner peripheries, the outer shell having an outwardly extended flange formed at its outer periphery, the inner shroud having an outwardly extended flange formed at its outer periphery and adapted to overlie and engage the outwardly extended flange formed at the outer periphery of the outer shell, positionin a plurality of fluid deflecting vanes between said shell and shroud members, moving the shell and shroud members toward each other to engage the outwardly extended flange formed at the outer periphery of the shroud with the outwardly extended flange formed at the outer periphery of the outer shell to position the vanes in firm contact with the surfaces of the shell and shroud members, securing together the outwardly extended flanges of the shell and shroud members to maintain the vanes in said firm contact with the shell and shroud members, metallurgically joining the vanes to the shell and shroud member, and thereafter removing the reenforcing flanges from the inner peripheries of the shell and shroud members and interrupting the outwardly extended flange formed at the outer periphery of the shroud in substantial alignment with the shroud and shell members.

7. The method of making an impeller for a fluid transmission which comprises forming a plurality of fluid energizing vanes each having bent over edges, forming outer shell and inner shroud members having reenforcing flanges at their inner peripheries, the outer shell having an outwardly extended attaching flange formed at its outer periphery, the inner shroud having an outwardly extended flange formed at its outer periphery and adapted to overlie and engage the attaching flange of the outer shell, positioning a plurality of said fluid energizing vanes between said shell and shroud members, moving the shell and shroud members toward each other to compress the bent over edges of the vanes into firm contact with the surface of the shell member and the confrontin surface of the shroud member and to engage the outwardly extended flange formed at the outer periphery of the shroud with the attaching flange of the outer shell, securing together the attaching flange and the outwardly extended flange of the shroud member to maintain the vanes in said firm contact with the shell and shroud members, metallurgically joining the vanes of the shell and shroud member, and thereafter removing the reenforcing flanges from the inner peripheries of the shell and shroud members and interrupting the outwardly extended flange formed at the outer periphery of the shroud in substantial alignment with the shroud and shell members.

8. A method of forming a rotatable part of a fluid transmission which comprises forming flanged shell and shroud members with the flange on one of said members forming a substantially radial yielding diaphragm, positioning a plurality of vanes between said members, pressing the flanges of the shell and shroud members together, said vanes being positioned between and in firm edge contact with the shell and shroud members, securing the said diaphragm oi the one member to the flange of the other member to hold all parts in position forming an assembly, releasing the pressing action, heating the assembly to join all contacting parts, and thereafter removing such portions of said diaphragm as are unnecessary to the operation of said rotatable part.

9. A method of forming a rotatable part of a fluid transmission which comprises forming flanged shell and shroud members with the flange on one of said members forming a substantially radial yielding diaphragm, positioning a plurality of vanes between said members, said vanes being positioned juxtaposed said diaphragm, po-' sitioning insulating material between the radial diaphragm and the vanes, pressing the flanges of the shell and shroud members together with the vanes between them in firm edge contact with the shell and shroud members, securing said diaphragm of the one member to the flange of the other member to hold all parts in position forming an assembly, releasing said pressing action, heating the assembly to join all contacting parts, and thereafter removing such portions of said diaphragm as are unnecessary to the operatio of said rotatable part.

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